Optical-testing apparatus and method



H. CLEMENT 7 QPTICAL TESTING APPARATUS AND METHOD 2 Sheets-Sheet 1 Sept. l6, 1930.

Filed Dec. 7 1926 awumtoz 7 Han; C/emen Z Z J mom Lu s p 6; 1930. H. CLEMENT 1,775,987

OPTICAL TESTING APPARATUS AND IETHOD Filed Dec. '7, 1926 2 Sheets-Sheet 2 awuwwtoz Hans CZemen Z Patented Sept. 16, 1930 UNITED STATES PATENT OFFICE HANS CLEMENT, OF NEW YORK, N. Y., ASSIGNOR TO GENERAL OPTICAL COMPANY, INC., A CORPORATION OF NEW YORK OPTICAL-TESTING APPARATUS AND lllETHOD Application filed December 7, 1926. Serial No. 153,080.

.the rapidity with which the subject is able to see and perceive outlines, and is a further 'measure not only of his acuity of vision but more particularly also of his rapidity of perception or speed of vision. This is of particular importance in the case of individuals who are engaged in such occupations as the driving of automobiles and like activities where prompt and accurate response is required to briefly occurring visual stimuli.

Ifthe person cannot see both clearly and ,quickly, obviously he cannot make the proper response; and if his vision does have both acuteness and speed of perception, he must also be able quickly totranslate the visual stimuli into muscular reflex actions, as a matter of safety to himself and others.

In the past there has been no satisfactory convenient device available for the rapid routine testing of this particular visual property of speed of perception. Objects of this invention are to provide an improved method and apparatus whereby such tests may be made more quickly and accurately. The device of my invention provides a simple attachment, cooperating with a standard optical test chart apparatus for the performance of this test, for accurately determining speed of vision per se, and more particularly in connection with and in relation to acuity in. general, as well. as also the promptness ofmuscular response. Such device consists of a special test chart adapted to be illuminated by the usual test chart lights, and an interval timer adapted to cooperate with the test chartlights for the illumination of thetest chart fora controlled brief interval. 1

Thus this invention provides an improved method and apparatus whereby tests of the rapidity of visual perception areconveniently and easily made in the course of routine optical testing of a subjects eyes.

Other objects and advantages of the invention, together with various features of construction and combinations of parts employed'in the carrying out of the invention, will be apparent from the following description when read in connection with the accompanying drawings, wherein:

Fig. 1 is a front view of an apparatus cmbodying the system of my invention;

F ig. 2 is a larger view of the interval timer and its connections to the test chart of the system of my invention;

Fig. 3 is a perspective view in front elevation of the special test chart of the system of my invention, and Fig. l is a diagram of the electric circuits of the device of my invention.

Referring to Fig. 1, I provide a chair 1 in which the subject may be seated, and an ophthalmic test device comprising a base portion 2, a chart cabinet 3, and testing apparatus combined therewith for routine optical testing as disclosed in the copending application, which became Patent No. 1,625,075, April 19, 1927. As disclosed therein, I provide a test cabinet, indicated at 3 in Fig. 1, which comprises a cabinet portion and changeable charts as disclosed in further detail in the copending application, which became Patent No. 1,692,929, dated November 27, 1928. The test cabinet 3 contains a pair test charts 5 therein. Electric current for energizingthe lights 4 is supplied from a convenientpower source through the wires 6 to asocket 7 in the stand 2 and through wires 8 in the stand 2, and wires 9 between the stand and the test cabinet. The wires 9 are provided with a separable connector 11 whereby the circuit may conveniently be broken for the insertion of other devices.

I further provide a switch 12 which may be of the through type having wires 14:

v venient pattern and which operates upon the pressure of'a 'butten 16 to close the switch] graduated indicia. on the'frdnt faceplate of ,the'tiir em ia At' heend oithef e e ted.t me interval; the timer mechanism; ar tomatically for a predetermined short time. The length of this time interval maybe adjusted byturm' ing efebntrelling knob 16", vvvillhe indicated by zipointer 16, which cooperateswith breaks the' circuit, which then will remain open. v The interval timerI.-16is.c0nnectedby riodsi or 't WiI'GS417 t0. the contaetscf the switch ee shown in Fig. 4;

v The interval ti adzi'jdtled' tq fX'j-re y Work are adapta bleifor i s re t m ereesh thisi piirpbee but second-tr), twelve setqit gfivhich is zihoiit the mi e hovvn in" Fig 3 .f h t eft e e the eu'xil'iary test ch art gi f 'timereqf iredfbr the de'vi'ce dffmy inveil ikim 7' f 1. Lfnrthjerjprevide an aiiX ilrytest chart l io f 'wiit r sp t am 18 is FPO- 10 separable wheres 1 :1

of, sewed; 19 iv n; 1 m "is instructedftoj' lcoktint their; ehlng inith'e chart cabinet and thenpre ss and'hold'downy the buttpn;l6ien theginterval timer. Upon'f actuatienfofithe timer; the ehart is i11umi-, netted{fer the bri'ef';predetermined time, the

ightin lc rw e be g, a m t y r' 'yi i i f i e"su i eiha 'tefchs erve". 4 i ,e Y li ii wl e meigi fop h i'r i fi lia i b y' .i hqe i j ft 'iz l o it o Pe m 1 e P P- ticiifhvieven nio'strepid Observer, and V V succeedinginspectienejare thengniitde With-' the tinier set', inealis -0f its amine-11m e .lo'll fi'i ve d n d d 1e teperceive cerrectly the teet' fignreo11"-the chart, The length 6f the; ilh rn" ;2ticn'peried,; ndicited by the: tl'm' je i w 'cep i n; mild i th s e m n h zri a 'e .p vtrio is e hje'ctsq rils'cgavvill be-eleemo J; th se skilled in the are, ejwide I verietyfbf i re; my b "m d 611 'd" i various:

7.2176. take enyfde' hichiis daptedte clofse el-nelec .b rie d t d; nte r '1 any; of thef timer s'witches iirie ranging from 'onie' eighth iof ja I filtili the siih jject is h e mpls 1 5.11 Within th t a di 21 f evi gj c f V "usual routinetestsffj e mehe 'mef nbergfpfthe c0 neeter opening "described in the' previously m n-1 epemng the "switch '12."

The interval timer "16 is then hsted for" e V ad -small interval value, preferably a fraction kgn 'h 5 progressive 5 depth; b

d theic eir ifinitheuiimijf shizm; fTiiis'S'f* "ive fb eenjcorr and act; v? n c n i ectien therewith, She j i i adeby itroduci lge,e ili ry'f ettd e -ij,-

j e cibinet thro iigh'thefroiiteight" 5 V .9 P Q m y" e-* siliiblYt Qfjp r i d n 2 i:v i i f s 7 refractive*ccrrectieng 1 firstfin" order tein eael'ire' th'iefpetientsiacuity .of visien ,.b'y meens of the jueii'al typeiefltestfl Conditions of illumination, no matter how long continued, while on the other hand if his vision is substantially free from refractive errors, and his speed of perception is high, the time required to identify a large character may be less than is conveniently measurable.

A series of determinations may thus be made upon a group of individuals and the average speed of perception determined. both with complete refractive correction, and with varying degree of incomplete correction.

.With such an average value determined, it is possible to distinguish those individuals whose speed of perception is much below the average. These are the individuals who may not see rapidly enough to perform proper movements to prevent error or danger, as for instance, in the operation of an automobile or other transportation device, or in the operation of dangerous machinery. These subjects may be warned accordingly and thereby the life and safety of both themselves and others safeguarded.

By the device of my invention 1 have produced a: convenient, simple means for the routine determination of the speed of visual perception of a subject.

While I have shown and described but a single embodiment of the device of my invention in the accompanying drawings and description, it is capable of various modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be imposed thereon as are required by the prior art or indicated by the appended claims.

I claim as my invention:

1. An optical test device comprising a test chart housing, a plurality of test charts adapted to refractive tests, an auxiliary test chart adapted to speed of perception tests, illuminating means. an interval timer, and means comprising a switch for inserting said timer in circuit with said illuminating means.

2. An optical test device comprising a test chart housing, a plurality of test charts adapted to refractive tests, an auxiliary test chart adapted to speed of perception tests, illuminating means, an interval timer having a switch and means comprising a time delay system, an associated controlling knob, and a starting button for closing said switch for predetermined time, and means comprising a removable switch system for inserting said timer in circuit with said. illuminating means.

3. An optical test device comprising a cooperating stand and test chart cabinet, a plurality of test charts therein, an auxiliary test chart comprising a frame, a rotatable disc therein, a finger grip for rotating said disc, a plurality of test figures on said disc, means comprising an opening in said frame for viewing said test figures independently, and means comprising a source of illumination and an interval timer for illuminating said auxiliary test chart over brief predetermined periods.

4. An optical test device comprising a cooperating stand and test chart cabinet, electric control and supply means in said stand and electric connections to said cabinet, electric lights in said cabinet associated with said supply means, means comprising separable connector plugs and a switch adapted to insertion in said electric circuits, means comprising an interval timer having a switch and lead wires associated with said timer switch for closing said circuit for predetermined intervals of time, and an auxiliary test chart cooperating with said cabinet and said electric lights.

5. In combination, a test chart housing, test charts, electric chart-illuminating means in the housing, an automatically acting interval timer, and means comprising a switch for inserting said timer in circuit with said illuminating means for the time controlled illumination of said charts, the said interval timer being of the type which after a predetermined interval of time opens a closed circuit and leaves it open.

6. In combination, a test chart holder, test charts cooperating therewith, means. compris ing an electric light for illumination thereof, an automatically acting interval timer switch, and switch means for associating said interval timer switch with said light for the control thereof, the-said timer switch including manually operable circuit-closing means, and

automatically operating circuit-opening means which leave the circuit open until the said circuit-closing means is againmanually operated.

7. The method of testing the speed of visual perception which consists in measuring the refractive error of a subjects eyes providing any required correction to obtain clear vision, adjusting asuitable test chart in accordance with the degree of refractive correction, illuminating the chart for a predetermined brief interval, changing such interval of illumination, and determining the shortest interval of time of illumination in which the chart can be accurately perceived.

8, The method of testing the speed of visual perception whichconsists in first determining the degree of optical correction of the eye under test, making such correction, present-ing a test chart having characters of a type and size chosen in accordance with the degree of optical correction, illuminating the presented test chart for a series of predetermined progressively increasing time intervals, and determining the shortest time interval in which the said characters of the test chart are correctly perceived.

9. The method of testing the speed of visual perception which consists in first determining the degree of optical correction of the eye under )test ,'i making'2such. correction, pre-' 1 sentinga 'te'st chart having characters Of a type and size chosen in accordance Withthe degree 'Of'optical correction, illuminating the priesented'test chart for a, seriesef predeter- 'mined progressively i-ncreasing, 5 time interills, determining theshortest time interval [in 'Whichthe-said: characters of thetest chart --are correctly perceiveclyend comparingi'the 7 iperceptiorrtimethus obiiziined-ofvairious sub gjects which have been} subjected to 'suchtest uthereby" to determine "the-relative degree of 5 speed With which they'correctlytperceive 'olo-v j'ects. i 1 :7 10.. The method of testing the speeds-ii :Vis-. "ualpereeptioirwhich consists ill-electrically illuminating a test chart, controllingthe elec .tric lighting :circuitihfsuch a manner as 'thereby to, illuminate the said chart fora series-0f progressively va-ryingshbrt-time i11- 'tervals, and n 0ti'11g'tlie shortest time interval e inwhich the-testgchart can be correctlyper 11. combifiationfl test-chart, an: elec- 7 trio lamp arranged to :illii'm-inate the test chart; an automatically acting interval timer switch in circuitgwith said lamp,-;smdzma nually operable-means :ior closing thefcircuit through the :said lamp} and timer switchythre said timer switch including"ineansjfor euto- I matically vopeningsuch closeducircuitafter a- :predetermined' interval-L o f time and for -therea fter'fledVihg' such geircu-itopen; V v 7 12. 111: combination, a,1te'st1chart, :an ele'c-' ,tric rrlamp er-ranged g-to' 'illumin atethetest. i chart, :an automaticallyactingvifitervalvtimer t switch; in circuitjrwithisseid lamp, and mangally '0perablegmeansistcr' -closing gthe ici'rciiit throughthe sai-idflamp and timer switchgithe H -sxid :tirnerg' switch including IIIGELIISffOI aiutomatically pe'ning"such closed-circuit after Ea v V-predeterrnined intervalQfetirne;aiidrfonthere- 1. atter-leaving suehicircuit 'epem and-thesaid V -tirneriswitch*-alse iiieludingpmaniiallyr open,

iflg the interval pf'itime? d rring which the "iseidicirfcuit, will frernain zclesed -beforesit ,is I automatically ope ned by Ithews'zrid ialltOllifitl- I I 

